Bacteriophage therapy

ABSTRACT

The subject invention provides a pharmaceutical composition comprising: (i) at least one bacteriophage strain(s) capable of producing a lytic infection in an adherent-invasive  Escherichia coli  strain; and (ii) a pharmaceutically acceptable carrier; for the treatment of inflammatory bowel disease. The subject invention further provides a method of treating inflammatory bowel disease comprising administering to a subject in need thereof at least one bacteriophage strain capable of producing a lytic infection in an adherent-invasive  Escherichia coli  strain thereby treating the subject. The subject invention also provides new bacteriophage strains.

FIELD OF THE INVENTION

The present invention lies in the field of bacteriophage therapy for use in the treatment of inflammatory bowel diseases.

BACKGROUND

Bacteriophages are viruses that infect bacteria by specific interaction.

Crohn's disease (CD), also known as regional enteritis, is an inflammatory disease of the intestines that may affect any part of the gastrointestinal tract from mouth to anus, causing a wide variety of symptoms. It primarily causes abdominal pain, diarrhea, vomiting, or weight loss, but may also cause complications outside the gastrointestinal tract such as skin rashes, arthritis, inflammation of the eye, tiredness, and lack of concentration.

Although the exact cause of CD is still unknown, a combination of environmental factors and genetic predisposition seems to cause the disease. CD is thought to be an autoimmune disease, in which the body's immune system attacks the gastrointestinal tract, causing inflammation; it is classified as a type of inflammatory bowel disease (IBD).

In patients with CD, abnormal expression of carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) is observed at the apical surface of the ileal epithelium and CD ileal lesions are colonized by pathogenic adherent-invasive Escherichia coli (AIEC).

There is no known pharmaceutical or surgical cure for Crohn's disease. In particular, neither IBD in general nor CD in particular can be treated with antibiotics (aiming at combatting pathogenic E. coli). Treatment options are restricted to controlling symptoms, maintaining remission, and preventing relapse.

SUMMARY OF THE INVENTION

The subject invention provides a pharmaceutical composition comprising: (i) at least one bacteriophage strain capable of producing a lytic infection in an adherent-invasive Escherichia coli strain; and (ii) a pharmaceutically acceptable carrier; for the treatment of inflammatory bowel disease (IBD).

The subject invention further provides a method of treating inflammatory bowel disease comprising administering to a subject in need thereof at least one bacteriophage strain capable of producing a lytic infection in an adherent-invasive Escherichia coli strain thereby treating the subject.

The subject invention further provides a bacteriophage strain P1 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4694 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

The subject invention further provides a bacteriophage strain P2 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4695 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

The subject invention further provides a bacteriophage strain P3 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4696 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

The subject invention further provides a bacteriophage strain P4 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4697 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

The subject invention further provides a bacteriophage strain P5 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4698 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

The subject invention further provides a bacteriophage strain P6 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4699 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

The subject invention further provides a bacteriophage strain P8 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4700 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

The subject invention also makes use of bacteriophage strain CLB_P2 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4675 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

For the purpose of the present invention, a variant of a bacteriophage strain is regarded as having the same lytic activity as said bacteriophage strain if it performs at least “+” against at least one of the AIEC strains LF82, 07081, 07082, 07076 and 06075 in the “In vitro assay of the infectivity of bacteriophages in AIEC strains” described in Example 3 below. In a preferred embodiment, a variant is regarded as having the same lytic activity if it performs at least “+” against all five AIEC strains LF 82, LF 06075, LF 07076, LF 07081 and LF 07082 (AIEC strains LF 06075, LF 07076, LF 07081 and LF 07082 are also abbreviated herein as 06075, 07076, 07081 and 07082, respectively). These AIEC strains have been deposited by Université Lille 2—Droit et Santé, 42 Rue Paul Duez, 59000 Lille (France) with the French National Collection at Institut Pasteur under Accession Numbers CNCM I-4712 (LF 82), CNCM I-4713 (LF 06075), CNCM I-4714 (LF 07076), CNCM I-4715 (LF 07081) and CNCM I-4716 (LF 07082).

For the purpose of the present invention, a variant of one of the bacteriophage strains P1 to P6, P8 and CLB_P2 is regarded as having the same phenotypic characteristics as said bacteriophage strain if it has at least 80% sequence identity on at least 70% of length, preferably at least 90% sequence identity on at least 80% of length and more preferably complete sequence identity on at least 90% of length (as determined by the BLAST algorithm) with the major capsid protein of bacteriophage wV8 (for variants of P1 to P6) or bacteriophage RB69 (for variants of P8) or bacteriophage JS98 (for variants of CLB_P2), as described below in the section “Identification of Major Capsid Proteins”.

In a preferred embodiment, a variant of a bacteriophage has the same lytic activity as the bacteriophage. In another embodiment, a variant of a bacteriophage has the same lytic activity and the same phenotypic characteristics as the bacteriophage.

DETAILED DESCRIPTION OF THE INVENTION

The subject invention provides a pharmaceutical composition comprising: (i) at least one bacteriophage strain capable of producing a lytic infection in an adherent-invasive Escherichia coli strain; and (ii) a pharmaceutically acceptable carrier; for the treatment of inflammatory bowel disease.

The subject invention further provides for a method of treating inflammatory bowel disease comprising administering to a subject in need thereof at least one bacteriophage strain capable of producing a lytic infection in an adherent-invasive Escherichia coli strain thereby treating the subject.

An “adherent-invasive Escherichia coli (AIEC) strain” as used herein should be understood as referring to an E. coli strain having a mean invasion potential of equal to or higher than 0.1% in a cell culture of the intestinal cell line 1-407. In other words, an AIEC strain has the ability to invade an intestinal cell culture of 1-407 with an invasion index equal or superior to 0.1% of the original inoculum (taken as 100%), when tested in accordance with the invasion assay described below in the section “Invasion Assay” (see also Darfeuille-Michaud et al. (2004), Gastroenterology 127:412-421).

Non-limiting examples of AIEC strains are LF82, LF82SK (deposited by Université d'Auvergne, 49 Boulevard Francois Mitterand, 63001 Clermont-Ferrand (France) with the French National Collection at Institut Pasteur under Accession Number CNCM I-4723), those listed in Table 1 herein below and those listed in the following itemization (cf. Darfeuille-Michaud et al. (2004), Gastroenterology 127:412-421, especially page 417, Table 2): LF31, LF71, LF123, LF138, LF9, LF15, LF28, LF50, LF65, LF119, LF128, LF130, LF73, LF100, LF110, LF134, LF105, LF49-2, LB11, and LF45-2. In one embodiment, the adherent-invasive Escherichia coli strain is LF82, 07081, 07082, 07076 or 06075, in particular LF82.

In one embodiment, the adherent-invasive Escherichia coli strain is present in the colon of the subject. In another embodiment, the adherent-invasive Escherichia coli strain is present in the ileum of the subject. In yet another embodiment, the adherent-invasive Escherichia coli strain is present in one or more intestinal parts (small and/or large) of the subject.

In one embodiment, the at least one bacteriophage strain is P1 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4694 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

In one embodiment, the at least one bacteriophage strain is P2 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4695 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

In one embodiment, the at least one bacteriophage strain is P3 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4696 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

In one embodiment, the at least one bacteriophage strain is P4 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4697 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

In one embodiment, the at least one bacteriophage strain is P5 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4698 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

In one embodiment, the at least one bacteriophage strain is P6 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4699 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

In one embodiment, the at least one bacteriophage strain is P8 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4700 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

In one embodiment, the at least one bacteriophage strain is CLB_P2 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4675 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

In one aspect, it is envisaged that the pharmaceutical composition comprises more than one bacteriophage strain, also named “a bacteriophage cocktail”. The bacteriophage cocktail of the present invention comprises any combination of two or more of P1, P2, P3, P4, P5, P6, P8 and CLB_P2 and variants thereof having the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics. Preferably, the bacteriophages in a bacteriophage cocktail intended for treatment of a specific subject or group of subjects will be selected on the basis of the AIEC strain or AIEC strains identified and selected for combatting.

Non-limiting examples of inflammatory bowel diseases are Crohn's disease (CD), ulcerative colitis (UC), chronic inflammatory bowel disease (chronic IBD) such as but not limited to microscopic colitis, celiac disease and vasculitis. In one embodiment, the IBD is CD or UC. In another embodiment, the inflammatory bowel disease is recurrence of ileal lesions after surgery (such as surgery for the removal of at least a part of the small intestine in CD patients). The recurrence can be measured by the Rutgeerts score.

In one embodiment, the IBD is not caused by a bacterial infection. This embodiment is based on the observation that IBD is an autoimmune disease which is not generally considered a bacterial disease. Instead, a bacterial infection may be concomitant to IBD, but is not necessarily the causative agent. This observation adds to the surprising finding of the present invention, namely applying bacteriophage therapy for the treatment of a disease which is not caused by bacteria.

For that reason, there can be—as an example—AIEC strains in family members of subjects suffering from an IBD, although these family members do not suffer from this disease. Likewise, AIEC strains can also be found in subjects neither suffering from IBD nor being related to subjects suffering from IBD, as can also be seen from Table 1 below.

“Treating” as used herein should be understood to encompass a decrease in one or more symptoms characteristic of the disease; a decrease in the rate of progression of the disease; recovery from the disease, cure from the disease, maintenance of remission and prophylaxis such as prevention of relapse.

A “subject” as used herein can be a male or a female subject. A subject can be a human being or any other mammal.

The dose and regimen of administration of a pharmaceutical composition of the invention will necessarily be dependent upon the therapeutic effect to be achieved (e.g. treatment of IBD) and may vary with the particular bacteriophage strains in the composition, the route of administration, and the age and condition of the individual subject to whom the medicament is to be administered.

A dosage for humans is likely to contain a dose of bacteriophage between 10⁴ and 10¹¹ plaque forming units (pfu). The desired dose may be presented as one dose per day or as multiple sub-doses administered at appropriate intervals.

In the context of the present invention the term “pharmaceutically acceptable carrier” relates to pharmaceutically-acceptable, non-toxic carriers, fillers or diluents, which are defined as vehicles commonly used to formulate pharmaceutical compositions for animal or human administration.

The pharmaceutical compositions of the present invention may further comprise pharmaceutically acceptable auxiliary agents, and optionally other therapeutic agents. Auxiliary agents, also named accessory ingredients, encompass those conventional in the art such as, but not limited to matrix-forming agents, thickeners, binders, lubricants, pH adjusting agents, protecting agents, viscosity enhancers, wicking agents, disintegrants, including non-effervescent and effervescent disintegrants, surfactants, anti-oxidants, wetting agents, colorants, flavoring agents, taste-masking agents, sweeteners, preservatives and so forth. In addition to being pharmaceutically acceptable, the auxiliary agents must be “acceptable” in the sense that they are compatible with the other ingredients of the composition, including the bacteriophage.

Pharmaceutical compositions and routes of administration include those suitable for or via oral (including buccal, sublingual and intraorbital), rectal, nasal, topical (including transdermal), ocular, otic, vaginal, bronchial, pulmonary or parenteral (including subcutaneous, intramuscular, intravenous, intradermal, intraperitoneal, intrapleural, intravesicular and intrathecal) administration or administration via an implant. The pharmaceutical composition or route of administration may be adapted to provide a targeted effect of bacteriophage strain of the invention. In a specific embodiment, a pharmaceutical composition of the invention is administered orally. The compositions may be prepared by any method well known in the art of pharmacy. Such methods include the step of bringing in association a bacteriophage strain of the invention with a pharmaceutically acceptable carrier and optionally one or more auxiliary agents.

Pharmaceutical compositions suitable for oral administration may be presented as discrete dosage units (dosage forms) such as pills, tablets, dragees or capsules, or as a powder or granules, or as a solution or suspension. The pharmaceutical composition may also be presented as a bolus or paste. The compositions can further be processed into a suppository or enema for rectal administration.

For parenteral administration, suitable compositions include aqueous and non-aqueous sterile injections. The compositions may be presented in unit-dose or multi-dose containers, for example sealed vials and ampoules, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of sterile liquid carrier, for example water, prior to use.

For transdermal administration, e.g., gels, patches or sprays can be contemplated.

Compositions or formulations suitable for pulmonary administration, e.g., by nasal inhalation, include fine dusts or mists which may be generated by means of metered dose pressurized aerosols, nebulizers or insufflators.

The invention further includes a kit comprising a pharmaceutical composition of the invention and instructions for the use of the composition for a use as hereinbefore described, optionally together with packaging material.

The subject invention further provides a bacteriophage strain P1 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4694 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

The subject invention further provides a bacteriophage strain P2 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4695 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

The subject invention further provides a bacteriophage strain P3 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4696 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

The subject invention further provides a bacteriophage strain P4 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4697 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

The subject invention further provides a bacteriophage strain P5 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4698 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

The subject invention further provides a bacteriophage strain P6 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4699 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

The subject invention further provides a bacteriophage strain P8 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4700 or a variant thereof, wherein the variant has the same lytic activity, preferably the same lytic activity and the same phenotypic characteristics as said bacteriophage strain.

EXAMPLES

The invention is further described in the following examples, which are not in any way intended to limit the scope of the invention as claimed.

Methods

Invasion Assay

The Intestine-407 (1-407) cell line derived from human embryonic jejunum and ileum was used as a model of undifferentiated intestinal epithelial cells. It was purchased from Flow Laboratories (Flow Laboratories Inc., Mc Lean, Va.).

Intestine-407 cells were seeded in 24-well tissue culture plates (Polylabo, Strasbourg, France) at a density of 4,105 cells/well and incubated for 20 hours. The cell monolayers were washed twice with PBS (pH 7.2). Bacterial invasion of epithelial cells was measured using the gentamicin protection assay (Falkow et al. (1987), Rev. Infect. Dis. 9 (Suppl. 5):S450-455). Each monolayer was inoculated in 1 mL of the cell culture medium lacking antibiotics with a multiplicity of infection of 10 bacteria per epithelial cell. After a 3-hour incubation period at 37° C. with 5% CO₂, the monolayers were washed 3 times with PBS. Fresh cell culture medium containing 100 μg/mL of gentamicin (Sigma, St. Louis, Mo.) was added for 1 hour to kill extracellular bacteria before lysis of the monolayers with 1% Triton X-100 (Sigma) in deionized water. This concentration of Triton X-100 had no effect on bacterial viability for at least 30 minutes. The samples were diluted and plated onto Mueller-Hinton agar plates to determine the number of colony-forming units. All results of E. coli invasive ability with Intestine-407 cell line were expressed as the percentage of intracellular bacteria compared with the initial inoculum, taken as 100%. All of the assays were performed at least 3 times in separate experiments.

Identification of Major Capsid Proteins

Virion proteins were obtained by boiling 60 μl of a suspension of 10¹¹ pfu/ml of each bacteriophage for 10 min. 20 μl of the suspension were run on a precast 4-12% polyacrylamide gel. The gel was stained with Coomassie blue and the major bands were excised, subjected to trypsin digestion and analyzed by mass spectrometry at the Institut Pasteur microsequencing facility.

The peptide masses obtained were compared with the information in protein databases, allowing the identification of the closest known protein, i.e. wV8 for P1 to P6 and RB69 for P8 and JS98 for CLB_P2 (see A. Villegas et al, Virology Journal 2009, 6:41 for characterization of wV8 and S. Zuber et al., Journal of Bacteriology 2007, 189:22, 8206 for characterization of RB69 and JS 98).

Alignment of the major capsid protein of bacteriophage wV8 with peptides obtained from mass spectrometry of the major capsid proteins of bacteriophages P1 to P6:

wV8: MLTNSEKSRFFLADLTGEVQSIPNTYGYISNLGLFRSAPITQTTFLMDLTDWDVSLLDAVDRDSRKAE P1:          FFLADLTGEVQSIPNTYGYISNLGLFR (SEQ ID NO: 2) P2:        SRFFLADLTGEVQSIPNTYGYISNLGLFRSAPITQTTFLMDLTDWDVSLLDAVDR (SEQ         ID NO: 20) P3: P4: P5: P6: wV8: TSAPERVRQISFPMMYFKEVESITPDEIQGVRQPGTANELTTEAVVRAKKLMKIRTKFDITREFLFMQ P1:         QISFPMMYFKEVESITPDEIQGVRQPGTANELTTEAVVR        TKFDITREFLFMQ         (SEQ ID NO: 4)                                 (SEQ ID NO: 5) P2:         QISFPMMYFKEVESITPDEIQGVRQPGTANELTTEAVVR        TKFDITREFLFMQ         (SEQ ID NO: 4)                                 (SEQ ID NO: 5) P3:         QISFPMMYFKEVESITPDEIQGVRQPGTANELTTEAVVR        TKFDITREFLFMQ         (SEQ ID NO: 4)                                 (SEQ ID NO: 5) P4:         QISFPMMYFKEVESITPDEIQGVRQPGTANELTTEAVVR        TKFDITREFLFMQ         (SEQ ID NO: 4)                                 (SEQ ID NO: 5) P5:         QISFPMMYFKEVESITPDEIQGVRQPGTANELTTEAVVR        TKFDITREFLFMQ         (SEQ ID NO: 4)                                 (SEQ ID NO: 5) P6:         QISFPMMYFKEVESITPDEIQGVRQPGTANELTTEAVVR        TKFDITREFLFMQ         (SEQ ID NO: 4)                                 (SEQ ID NO: 5) wV8: ALKGKVVDARGTLYADLYKQFDVEKKTVYFDLDNPNADIDAAIEELRMHMEDEAKTGTVINGEEIHVV P1: ALK       GTLYADLYK      KTVYFDLDNPNADIDASIEELR        TGTVINGEEIHVV           (SEQ ID NO: 6) (SEQ ID NO: 8)                (SEQ ID NO: 11) P2: ALK       GTLYADLYK                                    TGTVINGEEIHVV           (SEQ ID NO: 6)                               (SEQ ID NO: 11) P3: ALK       GTLYADLYK       TVYFDLDNPNADIDASIEELR        TGTVINGEEIHVV           (SEQ ID NO: 6)  (SEQ ID NO: 9)               (SEQ ID NO: 11) P4: ALK       GTLYADLYK                                    TGTVINGEEIHVV           (SEQ ID NO: 6)                               (SEQ ID NO: 11) P5: ALK       GTLYADLYK       TIYFDLDNPNADIDASIEELR        TGTVINGEEIHVV           (SEQ ID NO: 6)  (SEQ ID NO: 10)              (SEQ ID NO: 11) P6: ALK       GTLYADLYKQFDVEK TIYFDLDNPNADIDASIEELR        TGTVINGEEIHVV           (SEQ ID NO: 7)  (SEQ ID NO: 10)              (SEQ ID NO: 11) wV8: VDRLFFSKLVKHPKIRDAYLAQQTPLAWQQITGSLRTGGTDGVQAHMNTFYYGGVKFVQYNGKFKDKR P1: VDR           IRDAYLAQQTPLAWQQITGSLR                    FVQYNGK               (SEQ ID NO: 13)                           (SEQ ID NO: 18) P2: VDRLFFSK      IRDAYLAQQTPLAWQQITGSLRTGGTDGVQAEMNTFYYGGVKFVQYNGK               (SEQ ID NO: 14) P3: VDR             DAYLAQQTPLAWQQITGSLR                    FVQYNGK                 (SEQ ID NO: 15)                         (SEQ ID NO: 18) P4: VDR             DAYLAQQTPLAWQQITGSLR                    FVQYNGK                 (SEQ ID NO: 15)                         (SEQ ID NO: 18) P5: VDR             DAYLAQQTPLAWQQITGSLRTGGADGVQAHMNTFYYGGVKFVQYNGK                 (SEQ ID NO: 16) P6:                 DAYLAQQTPLAWQQITGSLRTGGADGVQAHMNTFYYGGVK                 (SEQ ID NO: 17) wV8: GKVHTLVSIDSVAATVGVGHAFPNVSMLGEANNIFEVAYGPCPKMGYANTLGQELYVFEYEKDRDEGI P1:                                             MGYANTLGQELYVFEYEKDR                                             (SEQ ID NO: 19) P2:                                             MGYANTLGQELYVFEYEKDR                                             (SEQ ID NO: 19) P3: P4: P5: P6: wV8: DFEAHSYMLPYCTRPQLLVDVRSDAKPD (SEQ ID NO: 1) P1:               PQLLVDVR (SEQ ID NO: 20) P2:               PQLLVDVR (SEQ ID NO: 20) P3:               PQLLVDVR (SEQ ID NO: 20) P4:               PQLLVDVR (SEQ ID NO: 20) P5:               PQLLVDVR (SEQ ID NO: 20) P6:               PQLLVDVR (SEQ ID NO: 20)

Alignment of the major capsid protein of bacteriophage RB69 with peptides obtained from mass spectrometry of the major capsid protein of bacteriophage P8:

RB69: MTTIKTKAQLVDKWKELLEGEGLPEIANSKQAIIAKIFENQEKDFEVSPEYKDEKIAQAFGSFLTEAE P8: RB69: IGGDHGYNAQNIAAGQTSGAVTQIGPAVMGMVRRAIPNLIAFDICGVQPMNSPTGQVFALRAVYGKDP P8: RB69: IAAGAKEAFHPMYAPDAMFSGQGAAKKEPALAASTQTKVGDIYTHFFQETGTVYLQASAQVTISSSAD P8:       EAFHPMYAPDAMFSGQGAAK       (SEQ ID NO: 22) RB69: DAAKLDAEIIKQMEAGALVEIAEGMATSIAELQEGFNGSTDNPWNEMGFRIDKQVIEAKSRQLKAAYS P8:                                                                 AAYS RB69: IELAQDLRAVHGMDADAELSGILATEIMLEINREVVDWINYSAQVGKSGMTNIVGSKAGVFDFQDPID P8: IELAQDLR                         EVVDWINYSAQVGK          AGVFDFQDPID (SEQ ID NO: 23)                  (SEQ ID NO: 24)         (SEQ ID NO: 25) RB69: IRGARWAGESFKALLFQIDKEAVEIARQTGRGEGNFIIASRNVVNVLASVDTGISYAAQGLASGENTD P8: IR   WAGESFK               QTGRGEGNFIIASR      (SEQ ID NO: 26)       (SEQ ID NO: 27) RB69: TTKSVFAGVLGGKYRVYIDQYAKQDYFTVGYKGANEMDAGIYYAPYVALTPLRGSDPKNFQPVMGFKT P8:    SVFAGVLGGKYRVYIDQYAKQDYFTVGYKGANEMDAGIYYAPYVALTPLR     NFQPVMGFKT    (SEQ ID NO: 28)                                        (SEQ ID NO: 29) RB69: RYGIGVNPFAESSLQAPGARIQSGMPSILNSLGKNAYFRRVYVKGI (SEQ ID NO: 21) P8: RYGIGVNPFAESSLQAPGARIQSGMPSILNSLGK

Alignment of the major capsid protein of bacteriophage JS98 with peptides obtained from mass spectrometry of the major capsid protein of bacteriophage CLB_P2.

JS98: MKKNALVQKWSALLENEALPEIVGASKQAIIAKIFENQEQDILTAPEYRDEKISEAFGSFLTEAEI CLB_P2: JS98: GGDHGYDATNIAAGQTSGAVTQIGPAVMGMVRRAIPHLIAFDICGVQPLNNPTGQVFALRAVYGKD CLB_P2:                                                             AVYGKD                                                             (SEQ ID NO: 35) JS98: PIAAGAKEAFHPMYAPNAMFSGQGAAETFEALAASKVLEVGKIYSHFFEATGSAHFQAVEAVTVDA CLB_P2: PIAAGAK JS98: GATDAAKLDAAVTALVEAGQLAEIAEGMATSIAELQEGENGSIDNPWNEMGFRIDKQVIEAKSRQL CLB_P2: JS98: KASYSIELAQDLRAVHGMDADAELSGILATEIMLEINREVIDWINYSAQVGKSGMTNTVGAKAGVF CLB_P2:  ASYSIELAQDLR                         EVIDWINYSAQVGK          AGVF  (SEQ ID NO: 36)                      (SEQ ID NO: 37)         (SEQ ID NO: 38) JS98: DFQDPIDIRGARWAGESFKALLFQIDKEAAEIARQTGRGAGNFIIASRNVVNVLAAVDTSVSYAAQ CLB_P2: DFQDPIDIR   WAGESFKALLFQIDKEAAEIAR    GAGNFIIASR             (SEQ ID NO: 39)           (SEQ ID NO: 40) JS98: GLGQGENVDTTKAVFAGVLGGKYRVYIDQYARSDYFTIGYKGSNEMDAGIYYAPYVALTPLRGSDP CLB_P2:             AVFAGVLGGKYRVYIDQYAR         GSNEMDAGIYYAPYVALTPLR             (SEQ ID NO: 41)              (SEQ ID NO: 42) JS98: KNFQPVMGEKTRYGIGINPFADPAAQAPTKRIQNGMPDIVNSLGLNGYFRRVYVKGI (SEQ ID NO: 34) CLB_P2:  NFQPVMGFKTRYGIGINPFADPAAQAPTKRIQNGMPDIVNSLGLNGYFR (SEQ ID NO: 43)

Example 1 Isolation of AIEC Strains

One hundred and sixty-six (166) adherent-invasive Escherichia coli (E. coli) strains, including E. coli strain LF82 (Table 1), were isolated as follows: The AIEC strains were isolated from fresh feces of CD patients, their family members and control subjects. The feces were diluted in tenfold dilutions up to −9. Each dilution was plated on different media. After incubation, colonies were sub-cultured, identified and the strains were tested for invasion capacity.

In detail, immediately after emission, fresh feces were introduced in a sterile container. The atmosphere was rendered anaerobic by addition of a moistened Anaerocult®. Samples were treated the day of sampling. About 1 g of feces were introduced in 9 mL of cysteinated Y4 strength Ringer solution in pre-weighed tubes; they were reweighed after introduction of the sample to determine its exact weight (first tenfold dilution).

Eight further tenfold dilutions were made and 0.1 mL of each dilution was plated on different non-selective and selective media incubated in appropriated conditions: Columbia blood agar (CS) and CSH agar incubated for one week under anaerobic conditions, MRS medium incubated for 48 h in an atmosphere enriched in CO₂, McConkey and Cetrimide agar incubated for 48 h in air. All incubations were done at 37° C. After incubation, colonies were counted, subcultured and identified by established phenotypic criteria.

A control subject was selected vis-à-vis a CD patient so that the control subject was of the same sex and age as the CD patient and had a similar family size as the CD patient (to take microflora variation within a family into consideration).

The protocol was approved by the local ethical committee in 2000. The patients were followed by the EPIMAD register, which is organized under an agreement between the Institut National de la Santé et de la Recherche Médicale (INSERM) and the Institut National de Veille Sanitaire (InVS) and is also supported by the Francois Aupetit Association, Lion's Club of Northwestern France, Ferring Laboratories, the Société Nationale Française de Gastroentérologie and Lille University Hospital.

TABLE 1 AIEC strains Invasion Invasion I-407 I-407 Culture Level of E. coli Total Count Number Reference Mean (%) SEM (%) Medium¹ Dilution (log UFC/g)² (logUFC/g)³ LF82 1.29 0.8 McC −4 5.7 5.9 AIEC isolated from CD patient 06259 C4-1 2.050 0.500 McC −5 5.87 10.52 06254 C34-12 2.163 0.738 Cet −2 2.91 10.14 06256 C34-2 0.550 1.70 McC −7 7.91 10.14 06072 C39-1 0.2075 0.147 McC −6 7.02 9.93 06073 C39-2 0.1374 0.097 McC −6 7.02 9.93 06075 C39-4 0.2334 0.165 McC −5 6.02 9.93 06076 C39-7 0.5900 0.417 Cet −2 3.02 9.93 06087 C42-1 0.1095 0.055 McC −5 5.82 9.58 06088 C42-2 0.1954 0.098 McC −5 5.82 9.58 06089 C42-3 0.1930 0.097 Cet −3 3.82 9.58 06398 C76-10 0.131 0.036 CS ana −5 6.09 9.99 06011 C84-2 0.2580 0.129 McC −6 6.96 9.23 06023 C97-1 0.1173 0.068 McC −7 8.14 10.03 06024 C97-2 0.1303 0.075 McC −6 7.14 10.03 06026 C98-1 0.1439 0.072 McC −6 7.2 9.34 06027 C98-2 0.1122 0.065 McC −6 7.2 9.34 06028 C98-4 0.2310 0.133 Cet −2 3.20 9.34 06029 C99-1 1.0657 0.615 McC −6 6.99 10.17 06030 C99-2 0.1613 0.081 McC −6 6.99 10.17 06031 C99-3 0.2330 0.135 McC −5 5.99 10.17 06033 C99-9 0.4667 0.269 Cet −2 2.99 10.17 06150 C187-13 0.6675 0.472 CS ana −7 7.93 9.97 06151 C187-14 1.0350 0.732 CS ana −7 7.93 9.97 06152 C187-15 0.4375 0.253 CS ana −7 7.93 9.97 06166 C190-1 0.2251 0.130 McC −8 9.28 10.98 06167 C190-2 0.1247 0.072 McC −8 9.28 10.98 06168 C190-3 0.1688 0.097 McC −7 8.28 10.98 06169 C190-4 0.1373 0.079 McC −6 7.28 10.98 06170 C190-6 0.7065 0.408 Cet −3 4.28 10.98 06171 C190-8 0.5827 0.336 Cet −2 3.28 10.98 06172 C190-7 0.5385 0.311 Cet −2 3.28 10.98 06173 C190-12 0.5182 0.299 CS ana −9 10.28 10.98 06280 C203-7 0.185 0.087 Cet −3 3.96 9.94 06281 C203-9 0.393 0.023 Cet −2 2.96 9.94 06283 C204-4 0.253 0.092 McC −6 7.00 9.78 06271 C205-2 0.153 0.052 McC −6 6.93 9.97 06278 C205-9 0.160 0.005 Cet −2 2.93 9.97 06351 C215-8 0.548 0.397 Cet −5 5.93 9.91 06352 C215-9 0.262 0.143 Cet −5 5.93 9.91 06353 C215-12 1.960 1.340 Cet −3 3.93 9.91 06354 C215-13 1.339 1.281 Cet −3 3.93 9.91 06356 C215-10 2.260 1.540 Cet −3 3.93 9.91 06357 C215-11 2.195 1.355 Cet −3 3.93 9.91 06358 C215-1 1.110 0.590 McC −6 7.93 9.91 06359 C215-2 1.523 0.928 McC −6 7.93 9.91 06360 C215-3 0.165 0.064 McC −4 4.93 9.91 06361 C215-4 0.315 0.135 McC −3 3.93 9.91 06362 C215-5 0.980 0.720 McC −3 3.93 9.91 07074 C43-1 1.5825 1.3675 McC −6 7.26 9.66 07075 C44-1 0.1822 0.0755 McC −5 6.01 9.91 07076 C44-2 0.5950 0.3350 McC −5 6.01 9.91 07077 C44-3 0.1432 0.0486 McC −4 5.01 9.91 07078 C44-4 0.3086 0.1764 McC −4 5.01 9.91 07081 C44-9 0.5525 0.2675 Cet −2 3.01 9.91 07082 C45-1 0.4675 0.0925 McC −5 5.94 9.46 07086 C45-9 0.2110 0.0842 Cet −2 2.94 9.46 07093 C50-2 1.3125 0.9375 McC −5 5.99 7.69 07035 C66-2 0.6475 0.3125 McC −7 8.01 9.53 07045 C71-1 0.2079 0.1226 McC −5 5.95 10.58 07046 C71-2 0.2030 0.0719 McC −4 4.95 10.58 07048 C71-5 0.2388 0.1382 Cet −2 2.95 10.58 07051 C100-11A 0.6325 0.3425 MRS −4 5.07 10.47 07003 C112-4 0.2513 0.0861 McC −5 6.14 10.88 07006 C112-10 0.8913 0.1863 Cet −2 3.14 10.88 07022 C121-8 0.1903 0.0448 Cet −5 6.14 10.88 07101 C55-1 0.678 0.022 McC −6 6.95 10.38 07103 C55-3 9.175 2.775 McC −5 5.95 10.38 07107 C55-8A 4.425 0.075 Cet −2 2.95 10.38 07111 C60-1 0.232 0.028 McC −6 6.84 8.20 07113 C60-3 0.340 0.105 McC −4 4.84 8.20 07126 C231-1 0.323 0.097 McC −7 7.94 10.62 07127 C231-2 0.141 0.030 McC −6 6.94 10.62 07128 C231-5 0.365 0.095 Cet −3 3.94 10.62 07134 C233-1 0.645 0.090 McC −3 3.98 6.18 07135 C233-3 1.510 0.390 McC −2 2.98 6.18 07136 C233-2 2.090 0.260 McC −3 3.98 6.18 07137 C233-11 1.108 0.168 CSH −3 3.98 6.18 AIEC isolated from family members of CD patients 06066 C22-9 0.2710 0.192 CS ana −7 7.94 10.12 06381 C33-5 0.465 0.185 Cet −2 2.90 9.46 06258 C35-5 0.873 0.428 McC −6 7.64 10.14 06086 C41-7 0.1242 0.072 Cet −2 2.91 10.14 06384 C47-2 0.180 0.010 McC −6 7.07 9.62 06386 C47-4 0.121 0.047 McC −5 6.07 9.62 06097 C64-2 1.4550 1.029 McC −5 6.03 9.80 06099 C64-5 0.1175 0.068 Cet −2 3.03 9.80 06100 C64-6 1.1225 0.794 Cet −2 3.03 9.8 06006 C81-1 0.2850 0.202 McC −5 5.96 9.64 06007 C81-2 0.3200 0.226 McC −5 5.96 9.64 06016 C85-1 0.7540 0.435 McC −7 8.01 10.16 06019 C85-5 1.4775 1.045 Cet −2 3.01 10.16 06394 C87-7 0.130 0.030 MRS −2 3.03 9.42 06020 C92-1 0.1253 0.072 McC −5 6.09 9.64 06021 C92-2 0.1678 0.097 McC −4 5.09 9.64 06022 C92-4 0.1229 0.071 McC −2 3.09 9.64 06396 C95-1 4.975 2.575 McC −6 7.1 9.75 06037 C102-1 0.6767 0.391 McC −6 6.90 8.55 06040 C102-7 0.2342 0.135 CS ana −6 6.9 8.55 06080 C107-2 0.5050 0.357 McC −6 7.1 9.55 06042 C107-3 0.1900 0.110 McC −6 7.1 9.55 06043 C107-5 1.7600 1.245 McC −6 7.1 9.55 06045 C107-10 0.1975 0.140 Cet −2 3.1 9.55 06046 C108-2 0.3925 0.278 McC −6 7.12 10.54 06049 C108-10 0.2425 0.171 CS ana −7 8.12 10.54 06057 C133-1 0.2475 0.175 McC −6 6.98 10.49 06101 C133-4 0.1809 0.090 Cet −2 2.98 10.49 06160 C189-2 1.3483 0.778 McC −6 7.07 10.19 06164 C189-16B 0.3295 0.190 CSH −8 8.07 10.19 06176 C191-4 0.3975 0.281 McC −5 5.96 10.34 06177 C191-5 0.3185 0.225 McC −5 5.96 10.34 06293 C207-6 0.175 0.111 Cet −2 2.93 10.13 06295 C208-6 0.116 0.047 Cet −2 2.91 10.57 06301 C211-1 0.285 0.242 McC −2 2.87 10.07 06329 C218-2 0.649 0.439 McC −6 6.88 10.06 06338 C218-13 0.208 0.047 Cet −5 5.88 10.06 06341 C218-16 0.304 0.218 Cet −4 4.88 10.06 07064 C225-1 0.1280 0.0058 McC −4 4.90 10.10 07065 C225-2 0.8354 0.7146 McC −4 4.90 10.10 07066 C225-5 0.9200 0.4150 McC −6 6.87 9.49 07067 C225-6 1.0792 0.5977 McC −5 5.87 9.49 07068 C226-1 0.1193 0.0334 McC −5 6.06 10.58 07073 C227-4 0.2164 0.1568 Cet −2 2.88 10.06 07120 C228-2 0.228 0.013 McC −2 3.17 9.72 07121 C229-1 0.126 0.012 McC −5 6.06 9.50 07122 C229-2 0.117 0.034 McC −4 5.06 9.50 07123 C229-7 0.190 0.045 Cet −5 6.06 9.50 07131 C232-5 0.190 0.122 Cet −2 2.98 9.60 07138 C235-1 0.658 0.193 McC −5 6.02 9.42 AIEC isolated from control subjects 06235 C174-6 2.833 2.468 Cet −2 3.05 10.59 06242 C177-1 0.251 0.175 McC −6 6.99 9.95 06103 C177-13 0.1461 0.073 CS ana −7 7.99 9.95 06105 C177-2 0.1571 0.079 McC −5 5.99 9.95 06106 C178-23 0.4527 0.261 CSH −5 6.03 10.24 06108 C179-7 0.1103 0.064 Cet −2 3.07 10.53 06142 C181-5 1.1525 0.815 Cet −3 4.01 9.96 06143 C183-12 0.2117 0.122 CSH −7 8.2 9.95 06121 C183-2 0.1867 0.108 McC −4 5.2 9.95 06122 C183-5 1.1025 0.780 Cet −2 3.20 9.95 06145 C184-17 0.1095 0.077 CSH −5 6.09 9.64 06146 C185-22 0.3933 0.227 CSH −5 5.88 9.88 06126 C185-1 0.6050 0.428 McC −4 4.88 9.88 06135 C185-2 0.4500 0.318 McC −5 5.88 9.88 06136 C185-3 0.4875 0.345 McC −2 2.88 9.88 06137 C185-6 0.3125 0.221 Cet −2 2.88 9.88 06127 C186-1 0.1063 0.053 McC −6 6.86 10.04 06129 C186-4 0.4700 0.332 Cet −3 3.86 10.04 06158 C188-15 0.1052 0.061 CS ana −6 6.94 9.60 06196 C192-11 0.508 0.279 Cet −2 2.92 9.44 06197 C195-1 0.206 0.157 McC −5 5.95 9.72 06198 C195-2 1.806 1.363 McC −4 4.95 9.72 06200 C195-6 2.498 1.482 Cet −2 2.95 9.72 06201 C196-1 0.218 0.105 McC −7 7.87 9.61 06204 C196-4 0.307 0.163 McC −5 5.87 9.61 06212 C197-1 3.133 1.438 McC −6 6.86 10.32 06213 C197-2 0.445 0.042 McC −6 6.86 10.32 06216 C197-6 0.886 0.782 Cet −2 2.86 10.32 06217 C198-1 0.143 0.112 McC −6 7.07 10.03 06218 C198-2 0.113 0.096 McC −6 7.07 10.03 06221 C199-3 5.367 3.132 McC −4 5.06 9.79 06222 C199-4 1.353 0.942 McC −3 4.06 9.79 06223 C199-5 2.980 2.122 McC −3 4.06 9.79 06224 C199-6 5.398 2.837 McC −3 4.06 9.79 06225 C200-1 0.538 0.277 McC −3 4.06 9.79 07032 C222-1 0.1038 0.0783 McC −6 7.14 10.88 07033 C222-2 1.2425 0.6575 McC −6 7.14 10.88 07125 C230-1 0.300 0.055 McC −5 6.0 10.2 ¹McC = McConkey Agar (bioMérieux) Cet = Cetrimide Agar (bioMérieux) CS ana = anaerobic Columbia blood agar MRS = Man Rogosa Sharp Agar (Oxoid) CSH = Columbia SH Agar ²The “level of E. coli” refers to the amount of the AIEC strain in the feces. ³“Total Count” refers to all bacterial species in feces.

CS ana culture medium has the following composition (per liter medium):

-   -   39 g of Columbia blood agar base (Oxoid)     -   5 g of glucose     -   0.3 g of cysteine chlorohydrate     -   5 g of agar     -   pH 7.0±0.2

The mixture is sterilized for 15 minutes at 121° C. Just before plating, 5% of horse blood is added.

CSH culture medium has the following composition (per liter medium):

-   -   39 g of Columbia blood agar base (Oxoid)     -   3 g of cysteine chlorohydrate     -   pH 6.8±0.2

The mixture is sterilized for 15 minutes at 121° C. Just before plating, 2 ml of sterile ammonium citrate solution (0.25 g/10 ml water) are added. After incubation, bacteria using cysteine (and releasing sulfide) result in black colonies on this medium.

Example 2 Phage Isolation

Phages were isolated from sewage water as follows: sewage water was filtered at 0.2 μm and mixed with an equal volume of 2× Luria-Bertani (LB) medium. This mixture was inoculated with a fresh culture of LF82 strain and incubated on a shaker at 37° C. overnight. Chloroform ( 1/10 volume) was added to the flask and placed on a shaker for one hour. The medium was centrifuged at 10,000 g for 10 min. 1 ml of the supernatant was collected and 1/10 vol. of chloroform was added. After a brief mix by vortex, the Eppendorf tube was centrifuged at 7,500 g for 5 min. To determine if phages were present in this extract, a drop (10 μl) of the supernatant was applied on an LB agar plate and allowed to dry. Using a platinum wire, the plate was streaked from the drop through the rest of the plate to isolate individual phages. 1 ml of a growing culture of LF82 strain was applied to cover the entire plate; the excess was removed and the plate was incubated at 37° C. overnight. One or two plaques were picked up and resuspended in 200 μl of SM buffer (10 mM TrisHCl pH7, NaCl 200 mM, gelatin 0.03%). 20 μl of chloroform was added in each tube and tubes were briefly mixed by vortex and centrifuged at 7,500 g for 5 min. 10 μl of the supernatant was applied on a LB plate and allowed to dry and the previous procedure was repeated at least three times. Once the majority of isolated plaques were homogenous, 10 μl of the last resuspended plaque were added to 1 ml of growing culture of LF82 strain at OD 0.1 at 600 nm. This culture tube was incubated at 37° C. for 2 to 4 hours until lysis occurred. After addition of 1/10 vol. of chloroform, the culture was transferred to an Eppendorf tube, centrifuged at 7,500 g for 5 min and cooled to 4° C., thereby obtaining the primary stock. Several dilutions of this stock were kept at 4° C. and used to infect a larger volume of culture in order to prepare larger amounts of phages. Seven (7) phages were obtained as follows:

-   -   vB_EcoM_LF82_P1 (herein before and after P1) deposited with the         French National Collection of Microorganisms at the Institut         Pasteur under Accession Number CNCM I-4694;     -   vB_EcoM_LF82_P2 (herein before and after P2) deposited with the         French National Collection of Microorganisms at the Institut         Pasteur under Accession Number CNCM I-4695;     -   vB_EcoM_LF82_P3 (herein before and after P3) deposited with the         French National Collection of Microorganisms at the Institut         Pasteur under Accession Number CNCM I-4696;     -   vB_EcoM_LF82_P4 (herein before and after P4) deposited with the         French National Collection of Microorganisms at the Institut         Pasteur under Accession Number CNCM I-4697;     -   vB_EcoM_LF82_P5 (herein before and after P5) deposited with the         French National Collection of Microorganisms at the Institut         Pasteur under Accession Number CNCM I-4698;     -   vB_EcoM_LF82_P6 (herein before and after P6) deposited with the         French National Collection of Microorganisms at the Institut         Pasteur under Accession Number CNCM I-4699; and     -   vB_EcoM_LF82_P8 (herein before and after P8) deposited with the         French National Collection of Microorganisms at the Institut         Pasteur under Accession Number CNCM I-4700.

CLB_P2, deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4675, and its isolation is described in detail in Maura et al. Environmental Microbiology (2012) 14(8), 1844-1854.

P1 to P6 phages belong to the wV8 bacteriophage family.

P8 belongs to the RB69 bacteriophage family.

CLB_P2 belongs to the JS98 bacteriophage family.

The classification into the wV8, RB69 and JS98 bacteriophage families was done based on the sequence of the major capsid protein.

Example 3 In Vitro Assays of the Infectivity of Bacteriophages in AIEC Strains

Plaque assay was carried out by contacting serial dilutions of bacteriophage solutions (from not diluted to 10⁻⁸ dilution) with a Petri dish which surface was covered by one bacterium. After overnight incubation at 37° C. plaques were counted. When the bacterium tested was the bacterial host (reference host) used to isolate bacteriophages it was considered that the plaque assay gave an efficiency of 100%. When the bacterium tested was not the original host, then the results were expressed by comparison to the reference host. A result greater than 80% (+++) means that the bacterium is a highly efficient host compared to the reference host, while a result between 0.1 and 80% (++) means that the bacterium is an efficient host, and a result below 0.1% (+) but above 0 means that the bacterium is a moderately efficient host, and finally 0 (−) means that the bacterium is totally resistant.

Results

Table 2 shows the result of the host spectrum of the 8 phages (as isolated/identified in Example 2) on 38 strains (out of the 166 strains isolated in Example 1, Table 1)

TABLE 2 Strains tested and effective efficiency of plating (EOP) obtained for each bacteriophage Bacterial Bacteriophage Strain P1 P2 P3 P4 P5 P6 P8 CLB_P2 LF82 +++ +++ +++ +++ +++ +++ +++ +++ 06023 − − − − − − − ++ 06030 − − − − − − + +++ 06033 ++ ++ ++ ++ ++ ++ + +++ 06066 − − − − − − +++ − 06072 − − − − − − + ++ 06073 − − − − − − + +++ 06075 +++ +++ +++ +++ +++ +++ + ++ 06088 ++ ++ ++ ++ ++ ++ − − 06089 ++ ++ ++ ++ ++ ++ − − 06122 ++ ++ ++ ++ ++ ++ − − 06150 − − − − − − + − 06351 ++ ++ ++ ++ ++ ++ − ++ 06353 + + + + + + − − 06354 − − − − − − − − 06356 ++ + + + + + − − 06357 + + + + + + − − 06358 ++ + + + + + − − 06359 ++ + + + + + − − 06361 + ++ + + + + + − 06362 − − − − − − − − 07045 − − − − − − − − 07046 − − − − − − − ++ 07048 − − − − − − − − 07051 − − − − − − − − 07075 − − − − − − − − 07076 ++ +++ ++ + + + +++ ++ 07077 − − − − − − − − 07078 ++ +++ + + + + + ++ 07081 ++ +++ ++ + + ++ +++ ++ 07082 +++ +++ +++ +++ +++ +++ +++ ++ 07107 +++ ++ +++ ++ +++ +++ − +++ 07126 +++ +++ +++ +++ +++ +++ − ++ 07127 +++ ++ +++ +++ ++ ++ − ++ 07128 − − − − − − − ++ 07134 − − − − − − − − 07135 − − − − − − − ++ 07136 − − − − − − − − 07137 − − − − − − ++ −

TABLE 3 number of strains infected by phages: Efficacy P1 P2 P3 P4 P5 P6 P8 CLB_P2 + 3 5 6 9 9 8 8 0 ++ 10 8 8 6 6 7 1 13 +++ 5 6 5 4 4 4 4 5 Total/38 18 19 19 19 19 19 13 18 Numbers indicate the number of strains infected by one bacteriophage

Example 4 In Vivo Replication of Bacteriophages in the Gut of Mice

In vivo replication of bacteriophages in the gut of mice was evaluated as follows: First, the strain LF82 was engineered to carry two antibiotic resistance genes conferring respectively resistance to Streptomycin and Kanamycin. This new bacterial strain was named LF82SK and its invasive properties were verified as to be similar to the original LF82 strain.

Three (3) groups of two (2) mice each:

Group 1: non-colonized mice+phages

Group 2: LF82SK colonized mice

Group 3: LF82SK colonized mice+phages

Streptomycin (5 g/L) was added to drinking water of all animals 3 days before day 0 and kept along the experiment.

At day 0, LF82SK was administered to Group 2 and 3 in order to allow the strain to colonize mice's gut.

At day 4, 200 μl of a cocktail of P2+P6 bacteriophages was administered to Group 1 and 3 (gavage solution 10⁸ pfu/ml) once in the morning and once in the afternoon. P2+P6 bacteriophages were also added to the drinking water (10⁸ pfu/ml). At day 5 in the morning, mice were sacrificed to evaluate the number of bacteria and bacteriophages in the ileum and in the feces.

Results:

Bacteria (E. coli):

Group 1: no bacteria;

Group 2: in ileum—10⁶ cfu/g organ; in feces—10⁸ cfu/organ;

Group 3: in ileum and feces: bacteria all lysed by phages.

Phages:

Group 1: in ileum—10⁶ pfu/g organ; in feces—10⁷ pfu/organ;

Group 2: no phages

Group 3: in ileum—10⁶ pfu/g organ; in feces—10¹⁰ pfu/organ;

In the feces, there were 100 times more phages in Group 3 than in Group 1 showing the multiplication of the phages in vivo.

Example 5 In Vivo Replication of Bacteriophages in the Gut of Mice

In vivo replication of bacteriophages in the gut of mice was evaluated as follows: 12 mice were dispatched into three (3) groups of four (4) mice each:

Group 1: non-colonized mice+phages

Group 2: LF82SK-colonized mice

Group 3: LF82SK-colonized mice+phages

Streptomycin (5 g/L) was added to drinking water of all animals 3 days before day 0 and kept along the experiment.

At day 0, LF82SK was given to mice of Group 2 and 3 in order to allow the strain to colonize mice's gut.

At day 4, bacteriophages (cocktail of P2+P6+P8 at 10⁸ pfu/mL each) were added in the drinking water of Group 1 and 3.

At day 5, mice were sacrificed to evaluate the number of bacteria and bacteriophages in the ileum and in the feces. 100 μl of ileal homogenates from the three groups were taken to extract whole DNA using Maxwell® 16 Tissue DNA purification kit from Promega.

Results:

Bacteria (E. coli):

Group 1: no bacteria;

Group 2: in ileum—3.2·10⁶ cfu/g of organ; in feces—1.2·10⁹ cfu/g of feces;

Group 3: in ileum and feces: bacteria all lysed by phages.

Phages:

Group 1: in ileum—1.4·10⁶ pfu/g of organ; in feces—5.2·10⁶ pfu/g of feces;

Group 2: no phages

Group 3: in ileum—2.6·10⁶ pfu/g of organ; in feces—1.0·10⁹ pfu/g of feces;

In the feces, there were 200 times more phages in Group 3 than in Group 1 showing the multiplication of the phages in vivo.

DNA extracted from ileal sections was used to run quantitative PCR using two sets of primers. One set of primers (SEQ ID NO: 30-31) served to amplify DNA from “all bacteria” present in the sample while the second set (SEQ ID NO: 32-33) was used to amplify specifically DNA from “E. coli” bacteria. After normalization, results were expressed as the ratio of E. coli versus all bacteria.

Group 1: qPCR amplifications were successful with all bacteria primers but not with E. coli primers. The ratio could not be calculated.

Group 2: qPCR amplifications were successful with both set of primers. The average ratio was 0.6 (60% of total bacteria were E. coli bacteria) Group 3: qPCR amplifications were successful with both set of primers. The average ratio was 0.1 (10% of total bacteria were E. coli bacteria). Note that one mouse displayed a ratio of 0.4 while the three others displayed much lower values (0.06; 0.0002; 0.002). In consequence bacteriophages were able to reduce the level of ileal colonization of LF82 bacteria by at least one order of magnitude in three mice out of four.

Example 6 In Vivo Assay of the Infectivity of Bacteriophages

Two cocktails of phages are selected for testing in wild-type (WT) mice and in CEACAM6 mice infected with the LF82 E. coli strain isolated from the CD patients.

In both WT mice and in CEACAM6 mice infected with the LF82 E. coli strain isolated from the CD patients, bacteriophages are administered to the mice by oral gavage in CMC. This kind of administration has many advantages: known quantity of bacteriophage administration and immediate gastric acidity neutralization. Phages are daily administered to the mice during the entire study.

-   -   Mice are sacrificed at 5 days after LF82 administration.     -   Main criteria: quantification of LF82 in ileal and colonic         adherent flora of the mice.     -   Minor criteria:         -   Evaluation of weight         -   Stool consistency.         -   Presence of fecal blood (macro and bio)     -   Luminal flora (conventional flora+LF82+phages)         -   At sacrifice: Macroscopic and histologic examinations,             adherent ileal and colonic flora+LF82+phages,         -   At sacrifice: Macroscopic and histologic examinations,             adherent ileal and colonic flora+LF82+phages,

Biological parameters of inflammation are monitored, and bacteriophage translocation in the mesenteric lymph nodes (MLN), liver and spleen is searched for.

Inflammation markers (MPO, pro-inflammatory cytokines IL-6, IL-12 and anti-inflammatory cytokines IL-10) are monitored. Bacteriophage and AIEC translocation in MLN, liver and spleen is searched for.

Follow-up of bacteriophage elimination takes place in stools of mice receiving the bacteriophage cocktail without the LF82 strain.

Example 7 In Vivo Assay of a Cocktail of Phages on the LF82 Strain

In vivo replication of bacteriophages (cocktail of P2+P6+P8+CLB_P2) in the gut of mice was evaluated as follows:

20 mice were dispatched into two (2) groups of ten (10) mice each:

Group 1: LF82SK-colonized mice

Group 2: LF82SK-colonized mice+phages

Streptomycin (5 g/L) was added to drinking water of all animals 3 days before day 0 and kept along the experiment.

At day 0, LF82SK was given to mice of both groups in order to allow the strain to colonize mice's gut.

At day 3, bacteriophages (cocktail of P2+P6+P8+CLB_P2 at 10⁸ pfu/mL each) were given to mice of Group 2 by gavage.

At day 4 and 7, 5 mice of each group were sacrificed to evaluate the number of bacteria and bacteriophages in the ileum, in the colon and in the feces. 100 μl of ileal and colonic homogenates from the two groups were taken to extract whole DNA using Maxwell® 16 Tissue DNA purification kit from Promega.

Results:

Level of LF82 in Stools:

At day 4 and 7 levels of LF82 were:

-   -   in group 1: 7 10⁹; 1 10⁹ cfu/g     -   in group 2: 8 10⁷; 5 10⁸ cfu/g         Level of Phages in Stools:

At day 4 and 7 levels of Phages were:

-   -   in group 1: none     -   in group 2: 5 10⁹; 6 10⁹ pfu/g

In the presence of the phage cocktail the level of LF82 in stools was significantly lower than in their absence showing that the phage cocktail was able to infect LF82 inside mice's gut.

Level of LF82 in Organs:

-   -   at day 4 levels of LF82 were:     -   in ileum of group 1: 100% of bacteria are E. coli (LF82)     -   in ileum of group 2: 20% of bacteria are E. coli (LF82)     -   in colon of group 1: 40% of bacteria are E. coli (LF82)     -   in colon of group 2: 2% of bacteria are E. coli (LF82)         at day 7 levels of LF82 were:     -   in ileum of group 1: 100% of bacteria are E. coli (LF82)     -   in ileum of group 2: 50% of bacteria are E. coli (LF82)     -   in colon of group 1: 25% of bacteria are E. coli (LF82)     -   in colon of group 2: 10% of bacteria are E. coli (LF82)         Level of Phages in Organs:         at day 4 levels of Phages were:     -   in ileum of group 1: none     -   in ileum of group 2: 7 10⁸ pfu/g     -   in colon of group 1: none     -   in colon of group 2: 5 10¹⁰ pfu/g         at day 7 levels of LF82 were:     -   in ileum of group 1: none     -   in ileum of group 2: 7 10⁸ pfu/g     -   in colon of group 1: none     -   in colon of group 4: 2 10⁸ pfu/g

At day 2 and 5 the level of LF82 was reduced in both ileum and colon in the group treated by phages. This shows that phages infect LF82 in gut sections and not only in stools. Concomitantly, the level of phages at day 7 stays as high as at day 2 showing that phage can last several days in the gut after a unique initial administration.

Example 8 In Vivo Assay of the Infectivity of Bacteriophages

In vivo assay of the infectivity of bacteriophages (cocktail of P2+P6+P8) in CEACAM6 mice infected with LF82SK was evaluated as follows:

48 mice were dispatched into three (4) groups as follows:

Group 1: non-colonized mice (8 mice)

Group 2: non-colonized mice+phages (12 mice)

Group 3: LF82SK-colonized mice (16 mice)

Group 4: LF82SK-colonized mice+phages (12 mice)

DSS (dextran sulfate) 0.25% was introduced in the drinking water 3 days before day 0 and kept along the experiment.

Streptomycin (5 mg) was administrated by oral gavage to all animals 1 day before day 0.

At day 0, LF82SK was administered to mice of Group 3 and 4 in order to allow the strain to colonize mice's gut.

At day 1, phages (cocktail of P2+P6+P8 at 10⁷ pfu/mL each) were administered once to each mouse of Group 2 and 4 by oral gavage in CMC. This kind of administration has many advantages: known quantity of bacteriophage administration and immediate gastric acidity neutralization.

At day 1, 4 mice from Group 3 were sacrificed to evaluate the number of bacteria in the ileum, in the colon and in the feces before the administration of phages.

At day 2, respectively 4, 6, 6 and 6 mice from Groups 1, 2, 3 and 4 were sacrificed to evaluate the number of bacteria and bacteriophages in the ileum, in the colon and in the feces.

At day 5, respectively 4, 6, 6 and 6 mice from Groups 1, 2, 3 and 4 were sacrificed to evaluate the number of bacteria and bacteriophages in the ileum, in the colon and in the feces.

100 μl of ileal, colon and feces homogenates from the four groups were taken to extract whole DNA using Maxwell® 16 Tissue DNA purification kit from Promega. Weight, stool consistency and presence of fecal blood were monitored daily. DNA extracted from ileal sections was used to run quantitative PCR using one set of primers (SEQ ID NO: 44-45) to amplify a specific gene (pMT1) from LF82. Results were expressed as the number of copies of this gene per gram of tissues.

LF82 pMT1 F  (SEQ ID NO: 44) CCATTCATGCAGCAGCTCTTT LF82 pMT1 R  (SEQ ID NO: 45) ATCGGACAACATTAGCGGTGT Results:

Values represent the median values obtained for each group of mice.

In group 1, neither LF82 nor Phages were detected along the experiment.

Level of LF82 in Stools:

At day 1: the level of LF82 in Groups 3 and 4 were 5 10⁹ and 6 10⁹ cfu/g resp.

At day 2, 3 and 5 levels of LF82 were:

-   -   in group 3: 3 10⁹; 5 10⁸; 5 10⁷ cfu/g     -   in group 4: 5 10⁵; 5 10⁵; 5 10³ cfu/g         Level of Phages in Stools:

At day 2, 3 and 5 levels of Phages were:

-   -   in group 2: 5 10⁵ pfu/g; not detected; not detected     -   in group 4: 1 10⁹; 1 10⁷; 5 10⁶ pfu/g

In the presence of phages the level of LF82 in stools was significantly lower than in their absence. Concomitantly, the level of phages was significantly higher in mice colonised by LF82 than in LF82-free mice. Both data confirmed that phages can infect LF82 in the gut.

Level of LF82 in Organs:

at day 2 levels of LF82 were:

-   -   in ileum of group 3: 2 10⁶ copies of pMT1/g     -   in ileum of group 4: 8 10⁴ copies of pMT1/g     -   in colon of group 3: 2 10⁷ copies of pMT1/g     -   in colon of group 4: 1 10⁵ copies of pMT1/g         at day 5 levels of LF82 were:     -   in ileum of group 3: 5 10⁴ copies of pMT1/g     -   in ileum of group 4: 8 10⁴ copies of pMT1/g     -   in colon of group 3: 6 10⁶ copies of pMT1/g     -   in colon of group 4: 2 10⁵ copies of pMT1/g         Level of Phages in Organs:         at day 2 levels of Phages were:     -   in ileum of group 2: not detected     -   in ileum of group 4: 8 10⁵ pfu/g     -   in colon of group 2: 5 10⁴ pfu/g     -   in colon of group 4: 5 10⁶ pfu/g         at day 5 levels of LF82 were:     -   in ileum of group 2: not detected     -   in ileum of group 4: not detected     -   in colon of group 2: not detected     -   in colon of group 4: 2 10⁴ pfu/g

At day 2, the level of LF82 was reduced in both ileum and colon in the group treated by phages. This shows that phages infected LF82 in gut sections and not only in stools. Concomitantly, the level of phages was significantly higher in mice colonised by LF82 than in LF82-free mice.

At day 5, the level of LF82 in ileum was too weak to see a difference between the two groups while in colon samples the level of LF82 was still reduced in the group that received phages compared to the groups that did not. Concomitantly, we could only detect phages in colon of mice colonised by LF82. This shows that the effect of phages in reducing LF82 can last several days after the initial administration.

Despite high colonisation level of LF82 observed in this experiment, no sign of colitis was observed in any of the groups.

EMBODIMENTS

The present invention in particular relates to the following embodiments:

-   -   1. A pharmaceutical composition comprising:         -   (i) at least one bacteriophage strain(s) capable of             producing a lytic infection in an adherent-invasive             Escherichia coli strain; and         -   (ii) a pharmaceutically acceptable carrier;         -   for use in the treatment of inflammatory bowel disease.     -   2. A composition according to embodiment 1 wherein the         adherent-invasive Escherichia coli strain is present in one or         more of the intestinal parts (small and large) of the subject.     -   3. A composition according to embodiment 1 wherein the         adherent-invasive Escherichia coli strain is LF82, 07081, 07082,         07076 or 06075.     -   4. A composition according to any one of embodiments 1 to 3         wherein the inflammatory bowel disease is Crohn's disease or         ulcerative colitis or recurrence of ileal lesions after surgery,         for example surgery for the removal of at least a part of the         small intestine in CD patients.     -   5. A composition according to any one of embodiments 1 to 4         wherein the composition comprises at least one of the         bacteriophage strain P1 deposited with the French National         Collection of Microorganisms at the Institut Pasteur under         Accession Number CNCM I-4694 or a variant thereof, wherein the         variant has the same lytic activity, preferably the same lytic         activity and the same phenotypic characteristics as said         bacteriophage strain P1, the bacteriophage strain P2 deposited         with the French National Collection of Microorganisms at the         Institut Pasteur under Accession Number CNCM I-4695 or a variant         thereof, wherein the variant has the same lytic activity,         preferably the same lytic activity and the same phenotypic         characteristics as said bacteriophage strain P2, the         bacteriophage strain P3 deposited with the French National         Collection of Microorganisms at the Institut Pasteur under         Accession Number CNCM I-4696 or a variant thereof, wherein the         variant has the same lytic activity, preferably the same lytic         activity and the same phenotypic characteristics as said         bacteriophage strain P3, the bacteriophage strain P4 deposited         with the French National Collection of Microorganisms at the         Institut Pasteur under Accession Number CNCM I-4697 or a variant         thereof, wherein the variant has the same lytic activity,         preferably the same lytic activity and the same phenotypic         characteristics as said bacteriophage strain P4, the         bacteriophage strain P5 deposited with the French National         Collection of Microorganisms at the Institut Pasteur under         Accession Number CNCM I-4698 or a variant thereof, wherein the         variant has the same lytic activity, preferably the same lytic         activity and the same phenotypic characteristics as said         bacteriophage strain P5, the bacteriophage strain P6 deposited         with the French National Collection of Microorganisms at the         Institut Pasteur under Accession Number CNCM I-4699 or a variant         thereof, wherein the variant has the same lytic activity,         preferably the same lytic activity and the same phenotypic         characteristics as said bacteriophage strain P6, the         bacteriophage strain P8 deposited with the French National         Collection of Microorganisms at the Institut Pasteur under         Accession Number CNCM I-4700 or a variant thereof, wherein the         variant has the same lytic activity, preferably the same lytic         activity and the same phenotypic characteristics as said         bacteriophage strain P8 and the bacteriophage strain CLBP2         deposited with the French National Collection of Microorganisms         at the Institut Pasteur under Accession Number CNCM I-4675 or a         variant thereof, wherein the variant has the same lytic         activity, preferably the same lytic activity and the same         phenotypic characteristics as said bacteriophage strain CLBP2.     -   6. A composition according to any one of embodiments 1 to 5         wherein the composition is for oral administration.     -   7. Bacteriophage strain P1 deposited with the French National         Collection of Microorganisms at the Institut Pasteur under         Accession Number CNCM I-4694 or a variant thereof, wherein the         variant has the same lytic activity, preferably the same lytic         activity and the same phenotypic characteristics as said         bacteriophage strain.     -   8. Bacteriophage strain P2 deposited with the French National         Collection of Microorganisms at the Institut Pasteur under         Accession Number CNCM I-4695 or a variant thereof, wherein the         variant has the same lytic activity, preferably the same lytic         activity and the same phenotypic characteristics as said         bacteriophage strain.     -   9. Bacteriophage strain P3 deposited with the French National         Collection of Microorganisms at the Institut Pasteur under         Accession Number CNCM I-4696 or a variant thereof, wherein the         variant has the same lytic activity, preferably the same lytic         activity and the same phenotypic characteristics as said         bacteriophage strain.     -   10. Bacteriophage strain P4 deposited with the French National         Collection of Microorganisms at the Institut Pasteur under         Accession Number CNCM I-4697 or a variant thereof, wherein the         variant has the same lytic activity, preferably the same lytic         activity and the same phenotypic characteristics as said         bacteriophage strain.     -   11. Bacteriophage strain P5 deposited with the French National         Collection of Microorganisms at the Institut Pasteur under         Accession Number CNCM I-4698 or a variant thereof, wherein the         variant has the same lytic activity, preferably the same lytic         activity and the same phenotypic characteristics as said         bacteriophage strain.     -   12. Bacteriophage strain P6 deposited with the French National         Collection of Microorganisms at the Institut Pasteur under         Accession Number CNCM I-4699 or a variant thereof, wherein the         variant has the same lytic activity, preferably the same lytic         activity and the same phenotypic characteristics as said         bacteriophage strain.     -   13. Bacteriophage strain P8 deposited with the French National         Collection of Microorganisms at the Institut Pasteur under         Accession Number CNCM I-4700 or a variant thereof, wherein the         variant has the same lytic activity, preferably the same lytic         activity and the same phenotypic characteristics as said         bacteriophage strain. 

The invention claimed is:
 1. A method of treating inflammatory bowel disease comprising administering to a subject in need thereof at least one bacteriophage strain capable of producing a lytic infection in an adherent-invasive Escherichia coli strain, thereby treating the subject, wherein the at least one bacteriophage strain is: the bacteriophage strain P1 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4694, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain P1; the bacteriophage strain P2 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4695, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain P2; the bacteriophage strain P3 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4696, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain P3; the bacteriophage strain P4 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4697, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain P4; the bacteriophage strain P5 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4698, or a variant thereof, wherein the variant has the same lytic activity as and at least 80% sequence identity on at least 70% of length said deposited bacteriophage strain P5; the bacteriophage strain P6 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4699, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain P6; or the bacteriophage strain P8 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4700, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain P8.
 2. A method according to claim 1, wherein the adherent-invasive Escherichia coli strain is present in one or more of the small intestine and the large intestine of the subject.
 3. A method according to claim 1, wherein the adherent-invasive Escherichia coli strain is LF82.
 4. A method according to claim 1, wherein the inflammatory bowel disease is Crohn's disease.
 5. A method according to claim 1, wherein the inflammatory bowel disease is ulcerative colitis.
 6. A method according to claim 1, wherein the administering comprises oral administration.
 7. A method of treating inflammatory bowel disease comprising administering to a subject in need thereof at least three bacteriophage strains capable of producing a lytic infection in an adherent-invasive Escherichia coli strain, thereby treating the subject, wherein the at least three bacteriophage strains comprise: the bacteriophage strain P2 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4695 or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said bacteriophage strain P2; the bacteriophage strain P8 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4700 or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said bacteriophage strain P8; and the bacteriophage strain CLB_P2 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4675 or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said bacteriophage strain CLB_P2.
 8. A method of achieving or maintaining remission of an inflammatory bowel disease comprising administering to a subject in need thereof at least one bacteriophage strain capable of producing a lytic infection in an adherent-invasive Escherichia coli strain, thereby treating the subject, wherein the at least one bacteriophage strain is: the bacteriophage strain P1 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4694, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain P1; the bacteriophage strain P2 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4695, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain P2; the bacteriophage strain P3 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4696, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain P3; the bacteriophage strain P4 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4697, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain P4; the bacteriophage strain P5 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4698, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain P5; the bacteriophage strain P6 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4699, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain P6; or the bacteriophage strain P8 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4700, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain P8.
 9. A method according to claim 8, wherein the adherent-invasive Escherichia coli strain is present in one or more of the small intestine and the large intestine of the subject.
 10. A method according to claim 8, wherein the adherent-invasive Escherichia coli strain is LF82.
 11. A method according to claim 8, wherein the inflammatory bowel disease is Crohn's disease.
 12. A method of achieving or maintaining remission of an inflammatory bowel disease comprising administering to a subject in need thereof at least three bacteriophage strains capable of producing a lytic infection in an adherent-invasive Escherichia coli strain, thereby treating the subject, wherein the at least three bacteriophage strains comprise: the bacteriophage strain P2 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4695 or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said bacteriophage strain P2; the bacteriophage strain P8 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4700 or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said bacteriophage strain P8; and the bacteriophage strain CLB_P2 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4675 or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said bacteriophage strain CLB_P2.
 13. A method according to claim 1, further comprising administering to the subject a bacteriophage strain CLB_P2 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4675, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain CLB_P2.
 14. A method according to claim 8, further comprising administering to the subject a bacteriophage strain CLB_P2 deposited with the French National Collection of Microorganisms at the Institut Pasteur under Accession Number CNCM I-4675, or a variant thereof, wherein the variant has the same lytic activity and at least 80% sequence identity on at least 70% of length as said deposited bacteriophage strain CLB_P2. 